Data corruption for NCLOB fields

[papersaltserver]

Hello,
we're working on a CAP project and decided to use @sap/cdx-mtx library for multitenancy. Our project heavily uses CSV files to seed initial data.
It was found that cds-mtx writes CSV data with hdb library to HDI Container to NCLOB field, then it reads the same CSV data and hdb library returns this data corrupted. For some files (every time the same), but not all some data has repeating symbols, e.g. 100002 instead of 10002, Serbiaan instead of Serbian. I've tried to open TENANT_FILES table with Database Explorer and exactly in place of symbol duplication DE truncates the field. I've also tried to open the same table with DBeaver and data looks fine in the database itself.
How to debug this? What should we check?